DCN October 2017 - Page 23

Green IT
applying a GREEN strategy: Grid
services, Renewable inputs, Energy
efficiency, Environmentally friendly
materials, Net zero energy solutions.
First, data centres typically
have capacities that are potentially
valuable to the electrical grid. They
have local generation capacity that
automatically helps in stabilising
the grid, as on-site production
reduces the load on the grid if
there is an unbalance. Taking this
possibility one step further, the
distributed excess capacity could
further mitigate the problem by
feeding the grid with electricity
input. Moreover, batteries installed
in UPS systems can serve as an
energy storage which is a valuable
complement to intermittent
renewable power generation based
on hydro, wind and solar energy.
Second, purchasing renewable
electricity makes a significant
difference to the carbon footprint
of computing. As large consumers
of electricity, data centres have an
impact on the supply of renewable
electricity either by purchasing
power from plants that would
otherwise not have been built, or
by purchasing power in markets
where renewable power supply
will expand as a market response
thanks to supporting incentives
and regulations.
Third, the ongoing structural
change that is caused by the
growth of IT-as-a-Service has
significant implications for
efficiency. Virtualisation and cloud
services have reduced the number
of dormant servers and increased
utilisation many times. As a result,
the same services can be provided
with less energy and less inputs.
Fourth, inputs to data centres
include not only electricity but
also machinery and construction
materials. Designing and building
data centres that use space
efficiently make one contribution
to green computing. Avoiding
concrete and choosing recyclable
materials and climate-friendly
refrigerants make another.
Fifth, net zero is feasible. This is
rather trivial from the perspective
of physics as very little mechanical
work is done by ICT-equipment.
Instead, essentially all electricity is
transformed to heat. By harvesting
and recycling - rather than
rejecting - the heat, a data centre
can close-the-loop and preserve
energy, thus reaching a net zero
energy outcome.
Motives and means
Business objectives depend
on circumstances. In Northern
Europe, sustainable solutions tend
to be commercially and financially
motivated. Green computing
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